Is Mathematics Alone a safe medium for exploring the frontiers of Science. Or should Observation and Hypothesis lead in front ?

[studiot]

Humblemum

 

The relatively new discipline of Simulation Modeling is also a better way forward than mathematical modeling imv.

 

 

Simulation is generally about process.

But underlying both simulation and other forms of modelling is the assumption that the model follows a sufficiently similar set of rules to that being modelled for the product of the processes to be put into correspondence in both systems.

 

In post#141 I posted a process that I maintain cannot be modelled by mathematical formulae alone.

 

I challenged the mathematicians here to offer such formulae if they disagreed.

 

I now challenge you to post a method of simulation for the process of mixing concrete to the desired consistency.

 

[Mellinia]

You do realize that there are set proportions for the amount of water in that example, with specific instructions to make it?

 

Not knowing something does not make it nonexistent.

[Humblemun]

Humblemum

 

 

 

Simulation is generally about process.

But underlying both simulation and other forms of modelling is the assumption that the model follows a sufficiently similar set of rules to that being modelled for the product of the processes to be put into correspondence in both systems.

 

In post#141 I posted a process that I maintain cannot be modelled by mathematical formulae alone.

 

I challenged the mathematicians here to offer such formulae if they disagreed.

 

I now challenge you to post a method of simulation for the process of mixing concrete to the desired consistency.

 

Funnily enough, I was a self-employed garden fencer after a being a Scientific Officer, so I used to mix concrete on a regular basis. I did it all by eye eventually of course. They'd be a multitude of reasons why I might want a particular mix to be runnier than another. It's from performing a task in the real world with real world ingredients many times over which gives a human being skill as a craftsman. Yes, I think I understand where you're coming from, mathematicians tend to forget that maths is just a model of reality. Reality isn't maths, but there's a surprising number of individuals who think so.

[studiot]

 

11:58 AM

You do realize that there are set proportions for the amount of water

 

Absolutely not.

That is the whole point.

 

The instruction is "add water until the consistency is correct"

 

This amount of water is not set and is different in every mix of concrete (allowing for total quantities)

[Mellinia]

 

Absolutely not.

That is the whole point.

 

The instruction is "add water until the consistency is correct"

 

This amount of water is not set and is different in every mix of concrete (allowing for total quantities)

For every type of 'consistency', there is a correct amount of water.

For every type of phenomena, there is maths to model it.

 

 

Reality isn't maths, but there's a surprising number of individuals who think so.

You do approximations because you don't lug a super computer with you all the time.

You might want to look up on how a plane is designed to ensure it's safety. The engineers don't make it by "feel" or simply Trial and Error, my dear chap. You don't feel that maths is important when you don't need high precision.

[studiot]

 

For every type of phenomena, there is maths to model it.

 

Go on then, post a formulae that will unequivocably determine the amount of water in 6MPa concrete, made with 20mm BS graded aggegtate, and zone2 sand. No additives, or pozzolans are allowed, cement to be OPC.Temperature on site +15 degrees C.

[Humblemun]

You do approximations because you don't lug a super computer with you all the time.

You might want to look up on how a plane is designed to ensure it's safety. The engineers don't make it by "feel" or simply Trial and Error, my dear chap. You don't feel that maths is important when you don't need high precision.

 

 

Wow, you're making approximations about myself. I've said elsewhere that I'm very respectful of the need for mathematics and that it is complementary to simulation modelling.

Edited August 29, 2013 by Humblemun

[Mellinia]

 

Go on then, post a formulae that will unequivocably determine the amount of water in 6MPa concrete, made with 20mm BS graded aggegtate, and zone2 sand. No additives, or pozzolans are allowed, cement to be OPC.Temperature on site +15 degrees C.

 

My dear chap, isn't it your job to find the relation between the concrete, aggregate, sand and water, so that anyone after you can make the same high quality you made?

But then again, knock yourself out.

http://www.scielo.br/scielo.php?pid=S1516-14392011000400001&script=sci_arttext

 

The real deal of math modeling can be found after seeing this:

http://en.wikipedia.org/wiki/Rock_mass_plasticity

Edited August 29, 2013 by Mellinia

[studiot]

Thank you for the link. Yes your source offers a specific amount of water. I note he even uses zone2 sand.

 

 

The final proportions of the ingredients (kg/cu.m) are as follows:

• Cement = 573;

• Sand = 435;

• Coarse aggregate = 1085 kg/cu.m;

• Water = 200.5 kg/cu.m including HRWRA;

• HRWRA = 8.6 kg/cu.m

• Water/cement ratio = 0.35.

 

Have you ever tried this proposed method?

 

Let us suppose you are on site and your concrete is arriving in 6 cu metre mixer lorries.

 

You are in charge so you give the instruction to add exactly 1203 kg of water to each lorry.

 

Now you are pumping this concrete into a large pour and the pump company says they will not pump concrete that has a workability of less than 65mm slump, whilst the resident engineer will reject all concrete that has a workability greater than 75mm slump.

 

Concrete is £80 per cubic metre so each lorryload discarded costs your company £480.

Your boss says that any discard will come out of your wages.

 

How much will you loose?

 

PS I have been in this situation on a large bridge deck pour and lost nothing after pouring over 1000 cu metres. But I did not add water your way, or by any mathematical formula.

 

Oh and by the way, all that stuff on plasticity has almost nothing to do with reinforced concrete engineering, even using the plastic design methods available in the codes.

Edited August 29, 2013 by studiot

[Mellinia]

Thank you for the link. Yes your source offers a specific amount of water. I note he even uses zone2 sand.

 

 

Have you ever tried this proposed method?

 

Let us suppose you are on site and your concrete is arriving in 6 cu metre mixer lorries.

 

You are in charge so you give the instruction to add exactly 1203 kg of water to each lorry.

 

Now you are pumping this concrete into a large pour and the pump company says they will not pump concrete that has a workability of less than 65mm slump, whilst the resident engineer will reject all concrete that has a workability greater than 75mm slump.

 

Concrete is £80 per cubic metre so each lorryload discarded costs your company £480.

Your boss says that any discard will come out of your wages.

 

How much will you loose?

 

PS I have been in this situation on a large bridge deck pour and lost nothing after pouring over 1000 cu metres. But I did not add water your way, or by any mathematical formula.

 

My dear, that was one type of mixture. I believe you did not read the discussion of the paper.

Experience is not inheritable, but information is, my dear. Experience that is written into concrete information has real value, and that is what maths and physics aim to do.

Chinese traditional medicine has that very flaw of not being able to translate experience into concrete information, but modern medicine has.

Edited August 29, 2013 by Mellinia

[Humblemun]

Shouldn't you two be on the bickering site?

[studiot]

 

My dear, that was one type of mixture. I believe you did not read the discussion of the paper.

Experience is not inheritable, but information is, my dear. Experience that is written into concrete information has real value, and that is what maths and physics aim to do.

Chinese traditional medicine has that very flaw of not being able to translate experience into concrete information, but modern medicine has.

 

 

So what was your answer to my question

 

If it is possible to specify an exact amount of water to achieve a desired workability, what is the formula?

[swansont]

My Professor of Simulation Modelling used to say that both were complementary. When he went for a contract, he could come out of the room and have a prototype working simulation model of the system described within 15 minutes and then show the potential clients. This factor would often give him the winning egde over the mathematical modellers. It suits people with very visual types of imagination, as opposed to natural mathematicians. I naturally prefer to imagine a mechanical system for understanding, whilst a mathematician doesn't, they can rely on the logic of the equations.

 

My professor said that the two methods were entirely different but would often come up with exactly the same answer/solution.

 

But your earlier link mentions meshes and algorithms. Surely you agree these are mathematical in nature. That means this is a subset of mathematical modeling.

[Mellinia]

 

So what was your answer to my question

 

If it is possible to specify an exact amount of water to achieve a desired workability, what is the formula?

 

I have shown an example of research and formula of one of the mixtures for that desired workability. (ps. it calculates a 0.35 water cement ratio for that type, with zone 2 sand)

It is possible to specify the amount of water.

Also, I have linked you to another link to calculate the stress you want your concrete to handle, and use those fluid equations(along with heat of hydration and crystal formation from chemistry) to calculate it.

My dear, the question is out, the equations and tips to solve given, and you're still asking me to do the maths homework to show that maths cannot produce a model for shear stress handling of concrete?

[Humblemun]

 

But your earlier link mentions meshes and algorithms. Surely you agree these are mathematical in nature. That means this is a subset of mathematical modeling.

That was the Wikipedia engineering example of the discipline. My Professor of Simulation Modelling used to solve problems of big multi-national companies. One story involved the problem a company was having with oil tankers worldwide, trying to make them as profitable as possible. Eventually after much research and modelling the problem was found to be the harbour masters taking "back handers" for a quicker entry into port.

 

There's certain problems which are better suited to simulation modelling and some better suited to mathematical modelling.

[swansont]

That was the Wikipedia engineering example of the discipline. My Professor of Simulation Modelling used to solve problems of big multi-national companies. One story involved the problem a company was having with oil tankers worldwide, trying to make them as profitable as possible. Eventually after much research and modelling the problem was found to be the harbour masters taking "back handers" for a quicker entry into port.

 

There's certain problems which are better suited to simulation modelling and some better suited to mathematical modelling.

Explain how bribery is a science problem and how it was solved without using math.

[Humblemun]

Explain how bribery is a science problem and how it was solved without using math.

I've probably said too much on the matter already.

Edited August 29, 2013 by Humblemun

[Mellinia]

That was the Wikipedia engineering example of the discipline. My Professor of Simulation Modelling used to solve problems of big multi-national companies. One story involved the problem a company was having with oil tankers worldwide, trying to make them as profitable as possible. Eventually after much research and modelling the problem was found to be the harbour masters taking "back handers" for a quicker entry into port.

 

There's certain problems which are better suited to simulation modelling and some better suited to mathematical modelling.

Note: There's game theory in maths that model game behavior which you can look up under maths. A classic example was the prisoners' dilemma

Edited August 29, 2013 by Mellinia

[Humblemun]

ok

[studiot]

 

Also, I have linked you to another link to calculate the stress you want your concrete to handle, and use those fluid equations(along with heat of hydration and crystal formation from chemistry) to calculate it.

My dear, the question is out, the equations and tips to solve given, and you're still asking me to do the maths homework to show that maths cannot produce a model for shear stress handling of concrete?

 

 

I didn't ask for stress calculations of any description, as they have nothing to do with how much water you need to add to the mix.

 

 

I have shown an example of research and formula of one of the mixtures for that desired workability. (ps. it calculates a 0.35 water cement ratio for that type, with zone 2 sand)

It is possible to specify the amount of water.

 

Yes but that will not give the correct answer, so perforce it is not a correct analysis or model.

 

That is why no-one in the whole world attempts to just add a specific amount of water when mixing structural concrete (or even fence post concrete).

 

What is actually done is a smaller amount of water than calculated by your method is added and then the final amount is 'trimmed' to suit after making workability measurements and then adding some more water.

This extra water will be different if every case.

 

Hence the instruction "add water until it is correct"

 

If you would like to know more I will happily tell you, but don't get on your high horse about a subject you are not expert in.

[Mellinia]

 

I didn't ask for stress calculations of any description, as they have nothing to do with how much water you need to add to the mix.

 

 

Yes but that will not give the correct answer, so perforce it is not a correct analysis or model.

 

That is why no-one in the whole world attempts to just add a specific amount of water when mixing structural concrete (or even fence post concrete).

 

What is actually done is a smaller amount of water than calculated by your method is added and then the final amount is 'trimmed' to suit after making workability measurements and then adding some more water.

This extra water will be different if every case.

 

Hence the instruction "add water until it is correct"

 

If you would like to know more I will happily tell you, but don't get on your high horse about a subject you are not expert in.

 

I believe you know that a higher water concrete mixture leads to less shear stress handling from experience? But I digress.

 

My dear, nobody said that it was a very accurate ratio (it gives the ratio, only with all those ingredients(HRWRAadded) for a 170mm Slump) , but as I said earlier, Science is never sure but it strives to improve. And that's why we need professionals like you to hand in data to the researchers.

Edited August 29, 2013 by Mellinia

[studiot]

 

 

I believe you know that a higher water concrete mixture leads to less shear stress handling from experience?

 

Not quite sure what you mean by this. There are many factors in play.

 

Here are some more proceedures from my experience.

 

Given some pieces of steel plate how would you generate a genuine flat surface to any desired degree of accuracy?

 

Given a brick, fresh from a kiln, it takes up moisture and expands slightly over time. This can lead to enormous forces if that brick is restrained as part of a wall.

How would you monitor this expansion over time, given that the necessary measurements are of the order of 1/10,000 of an inch?

 

Applied scientists (and researchers) face this sort of issue every day.

Edited August 29, 2013 by studiot

[ajb]

That means this is a subset of mathematical modeling.

It looks to me that simulation modeling is the same as mathematical modeling. One creates a computerised prototype and tests that before making real physical prototypes. This is all done with numerical or maybe algebraic methods that are hidden in a "black box" within the software being used. Thus, there is no obvious difference between mathematical modeling and simulation modeling.

[Delta1212]

It looks to me that simulation modeling is the same as mathematical modeling. One creates a computerised prototype and tests that before making real physical prototypes. This is all done with numerical or maybe algebraic methods that are hidden in a "black box" within the software being used. Thus, there is no obvious difference between mathematical modeling and simulation modeling.

It sounds like the difference between mathematical modeling and simulation modeling in that case would be akin to the difference between doing math and operating a calculator.

[ajb]

It sounds like the difference between mathematical modeling and simulation modeling in that case would be akin to the difference between doing math and operating a calculator.

I think so, but then I am not an expert in either of these fields. I await to be corrected.